Methods and apparatus for delivery of ocular implants

Abstract

An apparatus and methods for delivering ocular implants or microimplants. The apparatus is ergonomically designed for ease of use, and a simple manual depression of an actuator produces proportional movement of a linkage causing the implant or microimplant to be ejected through a cannula disposed at the desired location in the eye. Small gauge cannulas are provided for self-sealing methods of delivery.

Description

TECHNICAL FIELD [0001] The present invention relates to methods and apparatus for delivering solid or semi-solid materials into the eye. Specifically, the methods and apparatus can be used to introduce implants containing therapeutic or active agents, including bioerodible implants, into various locations within the eye, including the vitreous of the eye. BACKGROUND ART [0002] A primary difficulty in treating diseases of the eye is the inability to introduce drugs or therapeutic agents into the eye and maintain these drugs or agents at a therapeutically effective concentration in the eye for the necessary duration. Systemic administration may not be an ideal solution because, often, unacceptably high levels of systemic dosing are needed to achieve effective intraocular concentrations, with the increased incidence of unacceptable side effects of the drugs. Simple ocular instillation or application is not an acceptable alternative in many cases because the drug may be quickly washed o...

AI Technical Summary

Benefits of technology

[0007] The present invention meets these and other needs and provides methods and apparatus for easily, safely, and more precisely delivering an implant into the eye.

[0013] The invention also provides methods of delivery of an implant to a location of the eye. Various sites exist in the eye for implantation of a drug delivery device or implant, such as the vitreous of the eye, anterior or posterior chambers of the eye, or other areas of the eye including intraretinal, subretinal, intrachoroidal, suprachoroidal, intrascleral, episcleral, subconjunctival, intracorneal or epicorneal spaces. In one aspect of the invention, a cannula is used having an outer diameter of 0.032 inches or less. In other aspects of the invention, a cannula is used having an outer diameter of 0.028 inches or less or 0.025 inches or less. In yet another aspect of the invention, in cases where the cannula has a non-circular cross-section, the cannula has a cross-sectional area of up to 0.0008 square inches or more, depending on the particular cross-sectional geometry. The use of cannulas having such cross-sectional dimensions allows for self-sealing methods of implant delivery.

[0014] Accordingly, in one embodiment, a method of delivering an ocular microimplant into a patient's eye is provided which involves providing a cannula having a distal sharpened tip, lumen extending through the cannula, a microimplant that can be retained within the lumen, and a push rod that can be received through a proximal end of the cannula. The cannula is then used to puncture through the outer layer of a patient's eye with the cannula and inserted to a desired location within the patient's eye or is otherwise advanced to a desired location in a patient's eye. Once the cannula is positioned, the push rod is moved from the proximal end of the cannula toward the distal end of the cannula, thereby ejecting the microimplant from the cannula. After ejection, the cannula and push rod are removed from the patient's eye. In certain aspects, where cannulas having particular cross-sectional geometries are used, the puncture created by the insertion of the cannula into the patient's eye is self-sealing upon the removal of the cannula. Particular orientations of the cannula during insertion can aid in self-sealing. The cannula tip can further be configured to have particular beveled designs which further aid in the self-sealing method. Alternatively, methods of delivery are also contemplated where the resultant puncture is not self-sealing but can be sealed using known methods.

[0015] While the delivery apparatus according to the invention facilitates the inventive method of delivering an ocular microimplant, it is not necessary to the practice of inventive method. For example, one skilled in the art can also use a needle and plunger assembly, where the needle has dimensions corresponding to the described cannula.

[0016] The methods and apparatus of the invention provide numerous advantages, not least of which is providing for an easier, convenient, and less traumatic means for delivering implants into the eye. In certain embodiments, the self-sealing means of implant delivery can be achieved, which in addition to being less invasive and traumatic, offers less costly treatment by obviating the need for performing the procedure in a surgical setting.

[0017] The methods and apparatus of the invention also provide for a more controlled means of delivering implants into the eye. In particular, embodiments of the inventive apparatus are designed to provide a smooth, controlled delivery of the implant. Additional embodiments provide for safety features which include, among other things, user feedback upon the ejection of an implant and locking mechanisms which prevent backflow of eye fluid after ejection and / or which also prevent reuse of the applicator. Another advantage of the inventive apparatus is ease and flexibility of manufacture and assembly of apparatuses for delivery of different implants.

Problems solved by technology

A primary difficulty in treating diseases of the eye is the inability to introduce drugs or therapeutic agents into the eye and maintain these drugs or agents at a therapeutically effective concentration in the eye for the necessary duration.

Systemic administration may not be an ideal solution because, often, unacceptably high levels of systemic dosing are needed to achieve effective intraocular concentrations, with the increased incidence of unacceptable side effects of the drugs.

Simple ocular instillation or application is not an acceptable alternative in many cases because the drug may be quickly washed out by tear-action or is otherwise depleted from within the eye into the general circulation.

Suprachoroidal injections of drug solutions have also been performed, but again the drug availability is short-lived.

Such methods make it difficult to maintain therapeutic levels of drug for adequate time periods.

Wherever the desired location of implantation, typical methods of implantation all require relatively invasive surgical procedures, pose a risk of excessive trauma to the eye, and require excessive handling of the implant.

The drawbacks of such techniques for implant delivery are many-fold.

Extensive handling of the implant is necessitated in these techniques, creating a risk that the implant will be damaged in the process.

Many such implants are polymer-based and are relatively fragile.

In addition, it becomes inherently difficult using these methods to achieve reproducible placement from patient to patient.

Images